Self-contained temperature and pressure operated pinch valve

ABSTRACT

The present invention shows a self-contained, thermostatic temperature and pressure operated pinch valve in which the path of fluid flow through the valve may be automatically and directly controlled by the temperature and pressure of a flow material. Various conventional sensing mechanisms may be employed in the pinch valve of the invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.08/223,577, filed Apr. 6, 1994, entitled SELF-CONTAINED TEMPERATURE ANDPRESSURE OPERATED PINCH VALVE, abandoned, is a continuation ofapplication Ser. No. 09/001,754, filed Dec. 31, 1997, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to valves for use in heated andpressurized fluid flow, such as the conveyancing of steam. Inparticular, the present invention relates to a self-contained,thermostatic temperature and pressure operated pinch valve in which thepath of fluid flow through said valve may be automatically controlled bythe temperature and pressure of a flow material, said pinch valvecomprising:

(a) connection means adapted to incorporate said pinch valve within thepath of said flow material;

(b) a flow transport path for fluid flow through said valve, comprising:

i) an inlet for the transport of flow material into said valve;

ii) a flow adjustment means comprising a flexible tube surrounding anddefining at least a portion of said flow transport path, said flowadjustment means adapted to alternatively decrease the fluid flow inthat portion of said flow transport path defined by said flow adjustmentmeans upon an increase of pressure on a surface of the flow adjustmentmeans or increase the fluid flow in the path upon a decrease of pressureon a surface of the flow adjustment means; and,

iii) a flow measurement chamber within said flow transport path indirect pressure and temperature communication with said flow material,said flow measurement chamber being further provided with sensing meansin direct pressure and temperature communication with the flow material;and,

iv) an outlet for the transport of flow material from said valve; and,

(c) a closure chamber within said valve and at least partly surroundingsaid flow adjustment means, said closure chamber being further providedwith a closure means in direct operative communication with said flowadjustment means, and in operative communication with said sensingmeans;

wherein, said closure means is adapted to provide operative pressureupon said flow adjustment means in response to changes in thetemperature and pressure of the flow material as determined by saidsensing means.

2. Description of Related Art

Various forms of valves and steam traps are known which employ aplug-within-a-seat to interrupt the flow of steam. Where the steam ispressurized, however, the valve actuation means must be sensitive toboth temperature and pressure, and not just temperature alone. In orderto prevent the passage of live steam through the valve, without backingup a column of condensate, such a valve must follow the steam curve,i.e., the liquid-vapor transition of the fluid as a function of both itstemperature and pressure. A number of activation means are known whichare said to be sensitive to both temperature and pressure, i.e., theyfollow the steam curve. These include bimetallic discs, float, openbucket or inverted bucket, and bellows mechanisms.

Plug-within-a-seat valves and steam traps, however, are subject tofailure in systems containing any kind of dirt or grit, wherein a smallparticle of dirt can prevent the plug from seating correctly and causethe valve to malfunction.

An alternative to plug-within-a-seat construction, which does not sufferfrom this kind of failure, is the pinch valve. In such construction, thesteam flows through a conduit, at least a portion of which iselastomeric, and the flow can be interrupted by squeezing theelastomeric walls together (pinch). While this type of construction hasbeen employed in constructions in which a temperature sensitive fluidexpands to close off the elastomeric passageway, this known constructionis sensitive only to temperature, not the combination of temperature andpressure, and cannot be employed in applications which require the valveto follow the steam curve.

Applicant is not aware of the application of a pinch valve constructionin a valve or steam trap design in which the activation mechanism issensitive to temperature and pressure, such as the activationmethodologies enumerated above.

Certainly, one of the most pertinent references to the present inventionis U.S. Pat. No. 4,454,983 to Tarvis, entitled TEMPERATURE CONTROLLEDVALVE. This reference shows a control valve used as a steam trap with aflexible flow tube surrounded by a chamber filled with a fluid having ahigh co-efficient of thermal expansion in thermal contact with the flow.Changes in temperature of the flow will cause changes in the fluidvolume, constricting the flexible flow tube. While the device of thisreference is sensitive to the temperature of the flow, it is relativelyisolated from the pressure of the flow, and so does not follow thetemperature-pressure curve for the flow. Cited in the prosecution of theTarvis patent were U.S. Pat. Nos. 566,977 to Frohlich; 596,581 to Edson;875,320 to Burnet; 1,048,508 to Dunham; 1,120,707 to Frohlich; 1,198,918to Holmberg; 2,095,506 to Leutwiler; 2,590,215 to Sausa; 2,804,773 toDomingo and Peragallo; 2,884,866 to Patterson; 2,902,222 to Noakes;3,017,903 Steffens; 3,022,670 to Suttiffe; 3,145,967 to Gardner;3,353,560 to McCulloch; 3,514,034 to Cushman; 3,687,365 to Laessig; and,4,248,376 to Foller, as well as United Kingdom Patent 16,545 of 1903.

Of possible relevance are U.S. Pat. Nos. 2,842,331 to Anderson;3,901,438 to Christiansson; 4,114,640 to Forman; and 4,569,502 toElliott.

U.S. Pat. No. 2,842,331 to Anderson is entitled PINCH-OFF VALVE. Thisreference shows a valve used to mechanically pinch off a fluid flow.

U.S. Pat. No. 3,901,438 to Christiansson is entitledTHERMOSTAT-REGULATED RADIATOR VALVE FOR SINGLE OR DOUBLE CONDUIT CENTRALHEATING SYSTEMS. This reference shows a radiator valve regulated by athermostat. Working fluid is provided to a radiator through a flexibleconduit which can be pinched closed by a bimetalic cylinder in responseto the temperature of a thermodynamically-spent return fluid flow. Thedevice is, as reported, sensitive only to temperature, and thebimetallic element is in temperature contact only with the spent fluidflow. As such, it would be unsuitable in applications requiringoperation activated by a combination of temperature and pressure. Thatis, it would not be responsive to the steam curve.

Secondly, the device has two distinct flow paths: one for flow ofworking fluid into a working environment; and another, separate path forthe return flow of thermodynamically-spent fluid from the workingenvironment, subsequent to its thermodynamic function. It is the primarypurpose of the device of the Christiansson reference that the flow ofworking fluid in the intake path is controlled by the temperature, andthe temperature only, of the spent fluid in the return path.

U.S. Pat. No. 4,114,640 to Forman is entitled DRAIN VALVE. Thisreference shows a two-part device which may be attached to a flexibletube, such as the outlet tube of a medical solution drainage bagemployed in hospital and health care applications. The two part clip maybe squeezed together to interrupt fluid flow and protect the open end ofthe tubing from contamination. The device is intended for manualoperation, with no suggestion of any control by the temperature orpressure of the fluid.

U.S. Pat. No. 4,569,502 to Elliot is entitled PINCH VALVE. Thisreference shows a manually actuated pinch valve having a flexible valvebody. The device is intended for manual operation, with no suggestion ofany control by the temperature or pressure of the fluid.

U.S. Pat. No. 3,701,513 to Carter is entitled FUEL FEEDING APPARATUS.This reference shows a device for intermixing liquid fuel, air, and ameasured proportion of water for delivery to an internal combustionengine. The liquid fuel is supplied by way of a compressible elastomerictube.

U.S. Pat. No. 3,947,258 to Decker is entitled VAPOR STRIPPING ANDRECOVERY METHOD AND APPARATUS. This reference shows a method andapparatus for removing vapors from an air-vapor mixture.

U.S. Pat. No. 4,586,873 to Lepretre, Balzano, Caillault is entitledMIXER-EJECTOR WITH JET EFFECT AND VARIABLE CROSS-SECTION. This referenceshows a mixer-ejector with jet effect incorporates inductor nozzlesopening into a venturi profile conduit having in succession a highlyconvergent suction sleeve, a coupling wall and a diffuser. The couplingwall is a variable-profile venturi part, consisting of a hollow sleevemade of distortable elastic material in a casing with leaktight sealingand incorporates means for introducing a fluid into the enclosure formedby the sleeve and the casing.

U.S. Pat. No. 4,790,344 to Chauvier and Woodman is entitled FLUID FLOWREGULATOR. This reference shows a submersible cleaner in which the inletmay be regulated by pressurizing a chamber surrounding a collapsibleconduit.

U.S. Pat. No. 4,841,739 to Wallner is entitled AUTOMOTIVEAIR-CONDITIONING SYSTEM AND APPARATUS. This reference shows an autoair-conditioner, with a refrigerant circuit with a low-pressure portionand a high-pressure portion. A pressure-release valve with a blow-offoutlet is provided between the compressor and the condenser in thehigh-pressure portion.

U.S. Pat. Nos. 4,877,053, 4,895,341, and 4,899,783 are all based uponthe same original U.S. patent application to Yusko, Brown, Kalain, andWilliams are each entitled PINCH VALVE. These references shows somerather sophisticated pinch valves intended for use in biotechnologicalenvironments. These pinch valves are said to be useful because if thevalving mechanism does not come into contact with the material conveyed,then the valve does not become contaminated and require extensivesterilization and cleaning. The pinch valves of these references areintended to pinch off elastomeric conduits under the control of anoperator.

U.S. Pat. No. 5,107,883 to Shaw is entitled PINCH VALVE CONTROL SYSTEMFOR WATER LINE ISOLATION AND METHOD. This reference shows a pinch valvecontrol system for regulating the flow of water through the waterdistribution network of a building. Remote-controlled, fluid-operatedpinch valves are spaced at various locations throughout the waterdistribution network of the building and may be selectively operatedfrom a remote station to stop the flow of water in any pipe throughoutthe building's water distribution network. The use of pinch valvespermits water flow to be increased or decreased gradually and reduces oreliminates water hammer. The pinch valve is operated by compressed fluidwhich enters the sleeve around the pinch valve to stop the flow of waterin the pipe. To resume the water flow, the fluid in the pinch valve isreleased.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a self-containedpinch valve which is sensitive to changes in the temperature andpressure of the flow material.

The other objects, features and advantages of the present invention willbecome more apparent in light of the following detailed description ofthe preferred embodiment thereof.

According to the preferred embodiment of the present invention, there isprovided a self-contained, thermostatic temperature and pressureoperated pinch valve in which the path of fluid flow through said valvemay be automatically controlled by the temperature and pressure of aflow material, said pinch valve comprising:

(a) connection means adapted to incorporate said pinch valve within thepath of said flow material;

(b) a flow transport path for fluid flow through said valve, comprising:

i) an inlet for the transport of flow material into said valve;

ii) a flow adjustment means comprising a flexible tube surrounding anddefining at least a portion of said flow transport path, said flowadjustment means adapted to alternatively decrease the fluid flow inthat portion of said flow transport path defined by said flow adjustmentmeans upon an increase of pressure on a surface of the flow adjustmentmeans or increase the fluid flow in the path upon a decrease of pressureon a surface of the flow adjustment means; and,

iii) a flow measurement chamber within said flow transport path indirect pressure and temperature communication with said flow material,said flow measurement chamber being further provided with sensing meansin direct pressure and temperature communication with the flow material;and,

iv) an outlet for the transport of flow material from said valve; and,

(c) a closure chamber within said valve and at least partly surroundingsaid flow adjustment means, said closure chamber being further providedwith a closure means in direct operative communication with said flowadjustment means, and in operative communication with said sensingmeans;

wherein, said closure means is adapted to provide operative pressureupon said flow adjustment means in response to changes in thetemperature and pressure of the flow material as determined by saidsensing means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of one embodiment of the presentinvention.

FIG. 2 shows detail of the closure mechanism of the embodiment of FIG.1.

FIG. 3 shows the operating performance data of a prototype valve of FIG.1, superimposed upon a steam curve taken from the technical literature.

FIG. 4a shows a cross-sectional view of another embodiment of the deviceof the present invention with an iris mechanism employed as the closuremeans.

FIG. 4b shows detail of the iris mechanism.

FIG. 5a shows, in diagrammatic form, a prior art device employing afloat as the sensing means.

FIG. 5b shows an embodiment of the device of the present inventionemploying a float as the sensing means.

FIG. 6a shows, in diagrammatic form, a prior art device employing anopen bucket as the sensing means.

FIG. 6b shows an embodiment of the present invention employing an openbucket as the sensing means.

FIG. 6c shows a simplified embodiment of the device of the presentinvention employing an open bucket as the sensing means.

FIG. 7a shows, in diagrammatic form, a prior art device employing aninverted bucket as the sensing means.

FIG. 7b shows an embodiment of the present invention employing aninverted bucket as the sensing means.

FIG. 7c shows a simplified embodiment of the device of the presentinvention employing an inverted bucket as the sensing means.

FIG. 8a shows, in diagrammatic form, a prior art device employing abellows mechanism as the sensing means.

FIG. 8b shows an embodiment of the present invention employing a bellowsmechanism as the sensing means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As noted above, FIG. 1 shows a cross-sectional view of one embodiment ofthe present invention. This embodiment 10 is a self-contained,thermostatic temperature and pressure operated pinch valve 12. Thenovelty of this pinch valve resides in the ability of the valve 12 tofollow the steam curve. Thus, the path of fluid flow through this pinchvalve 12 may be automatically controlled by the temperature and pressureof the flow material.

In its basic embodiment, as shown in FIG. 1, the pinch valve 12 of thepresent invention comprises, first, at least one connection means 14adapted to incorporate the pinch valve 12 within the path of a flowmaterial. In practice, this connection means 14 may be a screw thread, asnap fitting, some type of welded connection, or any other connectionmeans known to the art. While some valves may be constructed to employonly one connection means having flow connections internal to thesystem, in many applications the valve is intended for installation as athroughput device, as shown in FIG. 1. In that embodiment 10, the pinchvalve 12 is shown with a connection means 14 at a first end thereof, anda second connection means 16 at the second end thereof.

The first connection means 14 and the second connection means 16 definethe outer limits of a flow transport path 18 for fluid flow through thepinch valve 12. This flow transport path 18 comprises an inlet 20,approximately coextensive with the first connection means 14, and anoutlet 22, approximately coextensive with the second connection means16. The inlet 20 provides access for the transport of flow material intothe pinch valve 12. The outlet 22 provides an egress for the transportof flow material from the pinch valve 12, as regulated by action of thepinch valve 12.

Also included in the flow transport path 18 is a flow adjustment means24 and a flow measurement chamber 26. In the illustrated embodiment 10,the flow adjustment means 24 comprises a flexible tube 28 surroundingand defining at least a portion of the flow transport path 18. Further,flow adjustment means 24 is adapted to alternatively decrease the fluidflow in that portion of the flow transport path 18 defined by the flowadjustment means 24 upon an increase of pressure on a surface 30 of theflow adjustment means 24 or increase the fluid flow in the flowtransport path 18 upon a decrease of pressure on a surface 30 of theflow adjustment means 24.

The flow measurement chamber 26, which is also part of the flowtransport path 18, is in direct pressure and temperature communicationwith the flow material. The flow measurement chamber 26 is furtherprovided with sensing means 32 in direct pressure and temperaturecommunication with the flow material In the illustrated embodiment 10,the sensing means 32 is shown as a plurality of bimetallic discs 34. Asknown in the art, an array of bimetallic discs can provide a response toonly the temperature of the fluid flow or, thermostaticly, to thetemperature and pressure of the fluid flow, depending upon how they arepositioned within the flow chamber. Thus, if the closure operation isindependent of the incoming flow, the operation is temperature dependentonly. Where the closure operation opposes the flow, however, as in theembodiment illustrated in FIG. 1, the device is sensitive to temperatureand pressure, and follows the steam curve.

The use of such bimetallic discs is well known in the manufacture ofplug-within-a-seat type valves, as are various other sensingmethodologies including, without limitation, float, open bucket,inverted bucket, and bellows type sensing devices. Such alternatesensing devices, illustrated in additional embodiments hereinafter,could be substituted by one skilled in the art for the bimetallic discs34 shown.

The pinch valve 12 is also comprised of a closure chamber 36, within thepinch valve 12 and at least partly surrounding the flow adjustment means24. This closure chamber 36 is further provided with a closure means 38in direct pressure communication with the surface 30 of the flowadjustment means 24. This closure means 38 is also in operativecommunication with the previously described sensing means 32.

The closure means 38 of the illustrated embodiment 10 of the presentinvention, is a mated pair of generally triangular members 40, one ofwhich is shown more clearly in FIG. 2. This triangular member 40, iscomprised of a substantially flat piece of suitable material, such asmetal, with a hole 42 therethrough proximate to a first vertex 44, and arounded shoulder 46 at a second vertex 48. At the third vertex 50, theclosure means 38 of the illustrated embodiment 10 is provided with anenlarged closure portion 52 extending perpendicularly from the generallytriangular member 40.

Again with reference to FIG. 1, a pair of mating triangular members 40are shown in operative position within the pinch valve 12 of theillustrated embodiment 10. In this position, the hole 42 of eachtriangular member 40 is attached to connection rod 54 by retainer 56,which may be a nut and bolt, a pin, or other joining mechanism known tothe art. The rounded shoulder 46 of the second vertex 48 of eachtriangular member 40 resides in a circumferential groove 58 cut in theinterior wall 60 of the pinch valve 12 of the illustrated embodiment 10.

In this position, further, the enlarged perpendicular closure portion 52of each triangular member 40 acts as a closure means 38, and is seen indirect pressure communication with the surface 30 of flow adjustmentmeans 24. As such, each closure means 38 is able to provide pressureupon the surface 30 of said flow adjustment means 24 in response tochanges in the temperature and pressure of the flow material asdetermined by the sensing means 32. Thus, as the bimetallic discs 34expand or contract with changes in the temperature and pressure of theflow material transported through the pinch valve 12, connection rod 54pulls or pushes upon each triangular member 40 at its first vertex 44.The confined positioning of the second vertex 48 of each triangularmember 40 within the circumferential groove 58 of the interior wall 60,translates the longitudinal motion of the connection rod 54 into apinching action of the closure means 38.

In this manner, the pinch valve 12 of the illustrated embodiment 10 isable to provide a self-contained, thermostatic temperature and pressureoperated pinch valve in which the path of fluid flow through the valvemay be automatically controlled by the temperature and pressure of aflow material.

FIG. 3 shows the operating performance data of a prototype valve of FIG.1, superimposed upon a steam curve taken from the technical literature.

FIGS. 4, 4b, 5b, 6b, 6c, 7b, 7c, and 8b disclose alternate embodimentsof the present indention. These alternate embodiments are similar to theembodiment discussed above in connection with FIGS. 1 and 2.Accordingly, a complete recitation of the features of the alternateembodiments is not repeated. Instead, like element numerals from FIGS. 1and 2 have been used in the Figs. which apply to the alternateembodiments to identify like elements for purposes of brevity andconvenience only, and is not limiting.

FIG. 4 shows a cross-sectional view of another embodiment of the deviceof the present invention with an iris mechanism 70 employed as theclosure means 38.

FIG. 5a shows, in diagrammatic form, a prior art device employing afloat 72 as the sensing means 32.

FIG. 5b shows an embodiment of the device of the present inventionemploying a float 72 as the sensing means 32.

FIG. 6a shows, in diagrammatic form, a prior art device employing anopen bucket 74 as the sensing means 32.

FIG. 6b shows an embodiment of the present invention employing an openbucket 74 as the sensing means 32.

FIG. 6c shows a simplified embodiment of the device of the presentinvention employing an open bucket 74 as the sensing means 32.

FIG. 7a shows, in diagrammatic form, a prior art device employing aninverted bucket 76 as the sensing means 32.

FIG. 7b shows an embodiment of the present invention employing aninverted bucket 76 as the sensing means 32.

FIG. 7c shows a simplified embodiment of the device of the presentinvention employing an inverted bucket 76 as the sensing means 32.

FIG. 8a shows, in diagrammatic form, a prior art device employing abellows mechanism 78 as the sensing means 32.

FIG. 8b shows an embodiment of the present invention employing a bellowsmechanism 78 as the sensing means 32.

Other features, advantages, and specific embodiments of this inventionwill become readily apparent to those exercising ordinary skill in theart after reading the foregoing disclosures. These specific embodimentsare within the scope of the claimed subject matter unless otherwiseexpressly indicated to the contrary. Moreover, while specificembodiments of this invention have been described in considerabledetail, variations and modifications of these embodiments can beeffected without departing from the spirit and scope of this inventionas disclosed and claimed.

What is claimed is:
 1. A self-contained, temperature and pressureoperated pinch valve in which the path of fluid flow through said valvemay be automatically controlled by the temperature and pressure of aflow material, said pinch valve comprising:(a) a flow transport path forfluid flow through said valve,said flow transport path including aflexible tube surrounding and defining at least a portion of said flowtransport path, said flexible tube adapted to alternatively decrease thefluid flow in that portion of said flow transport path defined by saidflexible tube upon an increase of pressure on a surface of the flexibletube or increase the fluid flow in the path upon a decrease of pressureon a surface of the flexible tube; and, (b) a sensor within the flowtransport path in direct temperature communication with the flowmaterial; and, (c) a closure in direct operative communication with saidflexible tube in operative communication with said sensor; wherein, saidclosure is adapted to provide operative pressure upon said flexible tubein response to changes in the temperature as determined by said sensorand line pressure of the flow material.
 2. The pinch valve of claim 1 inwhich said closure is pincher mechanism.
 3. The pinch valve of claim 2in which said pincher mechanism is comprised of two opposed faces. 4.The pinch valve of claim 1 in which said closure operates mechanically.5. The pinch valve of claim 1 in which said sensor is a plurality ofbimetallic discs.